1. Field of the Invention
The present invention concerns a method for positioning the breast for a biopsy in a mammography device. Moreover, the invention concerns a mammography device to implement this method.
2. Description of the Prior Art
When a pathological tissue variation or lesion is established in an x-ray image of the breast within the framework of a mammogram examination, for a definite diagnosis it is required in many cases to extract a tissue sample and to histologically examine this. For this purpose, in the stereotactic biopsy the breast is compressed and fixed between a compression plate and a bearing plate in a mammography device. The compression plate contains a rectangular opening via which the biopsy instrument can be inserted into the breast. In order to ensure that the tissue sample is extracted at the correct point, x-ray exposures are created from different directions during the procedure and the lesion is marked in the x-ray exposures. The precise penetration position and position depth of the biopsy instrument can be determined in this way. Before these x-ray acquisitions, the breast must now already be positioned so that the projection of the lesion is located within the projection of the rectangular opening. For correct positioning of the breast, it is therefore necessary to acquire one or more x-ray images from different directions before the acquisition of the x-ray images, which x-ray images serve exclusively to correctly position the breast between compression plate and bearing plate. However, every such x-ray acquisition entails an additional radiation exposure for the patient.